Feed collet and method of making the same



Apr. 3, 1923; 1,450,189 1 O. A. SMITH FEED COLLET AND METHOD OF MAKING THE SAME Filed Jan. 25, 1922 A-Y I vwwwoz Patented Apr. 3,1923.

OSCAR A. SMITH, OE EAST CLEVELAND, OHIO, ASSIGNOR TO THE NATIONAL ACME COMPANY, OF CLEVELAND, OHIO, A CORPORATION OF OHIO.

FEED OOLLET AN D METHOD OF MAKING THE I Application filed. January 23, 1922. Serial No. 531,089.

To all whom it may concern Be it known that I, OSCAR A. SMITH, a citizen of the United States, residing at East Cleveland, in the county of Cuyahoga and Stateof Ohio, have invented certain new and useful Improvements in Feed Collets and Methods of Making the Same, of which the following is a specification.

This invention relates to feed collets,

10 adapted particularly for attachment to feed tubes of machines such as automatic screw machines, automatic lathes, or other metal working machines, and to the method of making the same, an object thereof being toprovide an improved feed collet which will not loosen or unscrew during the operation of the machine.

A further object of this invention is to provide an improved feed collet, or pusher constructed for the purpose of feeding bar stock through the spindle of the machine which will automatically tighten itself to the feed tube of the machine to which it is attached when the machine is in operation.

Heretofore it was found in practice that devices of this type which are threaded or screwed to the end of the feed tube, have a tendency to loosen or unscrew on account of the vibration of the machine or the revolving of the spindle. This constant vibration' of the machine not only tends to loosen the feed collets from the tube but also causes the threads of the tubes to wear both laterally and circumferentially. Thus,

in all collets of this type heretofore used, the attaching means thereof comprised a body or shell constructed in the form of-atube, and having arigid or continuous wall throughout its periphery, the samebeing 40 provided with threads for screwing into the feed tube. Thus in addition to the greater expense involved in the production of such devices as compared with the present improvement, the further disadvantages of less durability, serviceab-ility and efiiciency were also present. I

As a result of the present invention the above disadvantages of feed collets heretofore used are eliminated. whichis accomplished by constructing the feed colletso as to have not only circumferential spring tension for gripping or holdingthe stock,

but also lateral spring tension for gripping the threaded portion of the tube. Instead of makingthe body portion or feed shell as 5 heretofore, in tubular form with a continuous rigid wall, in the present instance it is made either in the form of acoil with juxtaposed edges unconnected or in any other way so as to form a tubular body in like manner having a longitudinal slot throughout the length of the device.

Thus the present improvement is applicable to feed collets made either from solid stock or from tubing or rolled up into a coil from sheet metal, an important feature being to provide the device with a lengthwise extending slot or space throughout its entire length, the device being constructed throughout for expansible and contractible movement and having means for limiting this movement in one direction.

Other objects of this invention will appear in the following description thereof, reference being had to the accompanying drawings forming a part of this specification wherein like reference characters indicate corresponding parts in the several views and wherein Fig. 1 is a side view of an-embodiment of my improved Jfeed collet, parts. be- 30 ing broken away, the same beingillustrated vin position when screwed into the feed tube;

Fig. 2 is a front end view thereof; Fig. 3

is a rear end view thereof; Fig. 4 is a perspective view illustrating the device before being screwed into the feed tube; Fig. 5 is a rear end view of the construction shown in Fig. 4; and Fig. 6 is a view'of the blank from which the device may be'formed when made from sheet steel. As hereinbefore stated: while the present improvement is applicable to feed collets made'inany desired; manner as from solid stock, from tubing orformed up in a coil from sheet metal, it is illustrated by way of example as constructed from sheet metal as pressed sheetsteel, sincethis'form of collet has recent-ly'proven far superior to those made 'from the solid barby reason of the lessened cost of manufacture and the longevity and durability of the collet, and therefore it is shown rolled up from a blank 9 stamped out preferably from sheet ste l. This blank as illustrated in the present instance comprises a suitable body portion 10 terminating in a plurality of spaced finger pieces 11. Extending from an edge of the body.-, portion are one or more lugs or lobes 12 which may be either punched or pressed out or otherwise formed and which extend out a suitable distance corresponding to the width of the space through the threaded portion after the device is screwed into the feed tube.

The blank 9 is rolled up into the form of a coil as illustrated in Fig. 4 having a longitudinal slot or space extending throughout the length of the device.

If the collet were made from solid stock or tubing it would be split or slotted laterally its entire length as indicated at 13 in Figs. 1 and 2, and if made from unbrazed tubin or formed from sheet steel it would be le t in the shape of a coil allowing the required lateral slot or space 13 through its entire length. The body portion 10 of the collet is threaded at 14 to permit the same to be screwed into the end 15 of the feed tube, and the opposite end-or ripping end 16 of the device, whether ma e fromsolid stock, tubing or sheet metal requires respectively, the necessary borin slotting or shaping in order to accommodate the particular size of stock that is to be fed. The gripping end 16 may then be heated and compressed to the desired shape and spring tempered so that the bars of stock Wlll be gripped tight enough to allow the feed tube in conjunction with the collet to move the stock bars the required distance. For a detailed description of the construction of the collet fingers and the manner of forming the same reference may be had to the application of Charles J. Fancher and Robert A. Johnson, Serial No. 434,841, filed Jan. 3, 1921, and owned by The National Acme Compan also the assignee of this improvement. he particular flaring form at the end of the fingers is not a part of my invention since it constitutes the subject matter of an application of F ancher and Johnson about to be filed and also assigned to The National Acme Company.

As illustrated in Fig. 4 the juxtaposed or adjacent edges 17 and 18 are shown spaced from each other. The device is also expanded laterally at the body portion 10 so as to normall space the edge 17 from the lugs 12. This is done so that it will be necessary to compress the feeding device in order to permit the same to be screwed into the push tube.

Thus, the lugs 12, upon screwing the device into the push tube, act as bumpers or stops to limit or regulate the compression, as illustrated in Fig. 1. Hence by virtue of the fact that the body portion is spring tempered and is resiliently expansible and contractible there will always be a constant pressure or expansion at the threaded end of the device outwardly against the walls of the threaded portion of the tube. operation therefore the circumferential strain or stress resulting from gripping and pushing the bars forward in addition to the centrifugal force of the revolving spindle in which the feed or push tube is housed is effective to still further clamp or tighten the device into its support.

As a result of the foregoing it will be seen that the present improved feed collet is provided with a resilient gripping portion 16 for gripping and feeding the stock and also a resilient or expansible and con tractible gripping portion 14 for attachment to the feed tube, the collet being in the form of a coil or tube, having a pair of juxtaposed unconnected edges extending throughout its length. Hence the device operates as a coiled spring inasmuch as it automatically and resiliently attaches itself to the feed tube thereby eliminating the danger of loosening or unscrewing.

The lugs 12 may be formed in various ways. That is to say they may be stamped out at the time that the blank shown in Fig. 6 is stamped, or subsequent thereto, theymay be pressed out from the metal, or they may be pressed out from the metal after it is coiled into the form shown in Fig. 4, and these lugs or projections serve not only the purpose heretofore referred to, but also serve to permit the end of the collet to be threaded, since in threading the collet the normal diameter of the collet must be maintained during the threading operation. Therefore it is necessary that the spaced edges of the collet be held in close contact or engagement when the end of the collet is being threaded and it follows that during the threading operation the edge 17 of the collet may be clamped in tight engagement with the projections 12 so that the end of the collet may be easily threaded.

As hereinbefore stated in making the collet of sheet metal, ablank such as that shown in Fig. 6 is stamped either with or without the projections 12 thereon. It is then either rolled up or coiled into the form shown in Fig. 4, and if the end is to be threaded at this time and before the further forn'i'atio-n of the fingers, the collet is,placed in a machine adapted for the purpose and a suitable shoulder cut therein, and then the end is threaded or if preferred the shoulder may be formed by compressing the blank shown in Fig. 6 or the shoulder may be formed after the collet is rolled or bent, but as this forms no part of my invention but is the subject of an application of Fanpressed to provide the resilient, tapered gripping portion, shown herein as spaced. tapered, fingers, preferably having an elongated gripping surface 13.

Although I have described my invention in 1ts preferred form, it is to be understood that I do not limit myself to the construction herein shown and described except in so far as defined in the claims or embraced within the scope thereof.

I claim as my invention:

1. A feed collet having a resilient gripping portion for the work and an expansible and contractible gripping portion for attachment to its support.

2. A feed collet comprising a hollow body having a pair of adjacent edges, spaced throughout its length.

3. As an article of manufacture, a feed collet having a resilient gripping portion for attachment toits support.

4. As an article of manufacture, a feed collet having a resilient threaded gripping portion for attachment to its support.

5. A feed collet comprising a body having a bore therethrough, and having a pair of juxtaposed unconnected edges extending the entire length of the body.

6. A feed collet comprising a hollow body having a pair of adjacent, edges spaced throughout its length, said body constructed for expansible and contractible movement.

7. A feed collet comprising a hollow body having a pair of adjacent edges spaced throughout its length, said body constructed for expansible and contractible movement, and means for limiting such contractible movement.

8. A feed collet comprising a hollow body having a pair of adjacent edges spaced throughout its length, said body constructed for expansib-le and contractible movement, and means projecting from an edge of said body for limiting such contractible movement.

9. A feed collet comprising a resilient body having a bore the-rethrough, and having a pair of juxtaposed unconnected edges extending substantially the entire length of the device.

10. A feed collet having a gripping portion adapted to grip the work, and expansible and contractible means for attachment to its support.

11. A feed collet having a gripping portion adapted to grip the work, and expansible and contractible means for attachment to its support, and comprising a threaded body portion constructed in the form of a coiled spring.

12. A feed collet having a gripping portion shaped to conform to the shape of the work to be gripped, and expansible and contractible means for attachment to its support, said means comprising a threaded body portion having a longitudinal slot extending throughout its length, and aprojecting lug extending into said slot.

13. A feed collet comprising abody formed from sheet metal and having the iuxtaposed edges unconnected.

1 1.A feed collet comprising abody formed from sheet metal and having the juxtaposed edges unconnected, said device constructed to be expansible and contractible throughout its length.

15. A feed collet comprising a body formed from sheet metal and having the juxtaposed edges unconnected, and constructed to be. expansible and contractible throughout its length, and means for limiting such contractible movement.

16. A feed collet comprising a hollow body having a slot extending throu houtits length thereby to form said device into substantially acoiled spring.

17. A feed collet comprising a body portion having a gripping portion extending therefrom adapted to grip the work, and also having-means for attachment to its support, said body portion having a pair of spaced juxtaposed edges, and a projection therebetween.

18'. A feed collet comprising a body portion bent or formed from a sheet metal blank having a gripping portion extending therefrom adapted to grip the work, and also having means for attachment to its support, said body portion having a pair of spaced, juxtaposed edges, and a projection therebetween.

19. A feed collet consisting of a tubular sheet metal member having spaced edges from end to end, and comprising a body portion and a gripping portion, the body portion having a shouldered and resilient threaded end, and the gripping portion comprising a tapered resilient gripping portion.

20. A feed collet consisting of a tubular sheet metal member having spaced edges from endto end, and comprising a body portion and a gripping portion, the body portion having a shouldered and resilient threaded end, and the gripping portion comprising a tapered, resilient portion terminating in an elongated gripping surface having the shape of the 'work to be fed.

21. A feed collet consisting of a tubular sheet metal member having spaced edges from end to end, and comprising a body portion'and a gripping portion, the body portion having a shouldered and resilient threaded end, and the gripping portion comprising a plurality of tapered resilient fingers spaced from each other.

22. The method of making a feed collet which consists in forming a tubular member witha body portion and a tapered gripping portion, said tubular member having spaced edges from end to end.

23. The method of making a feed collet which consists in forming a tubular member with a plurality ofspaced, resilient gripping portions, and with spaced edges from end to end.

2a. The method of making a feed collet which consists in stamping from sheet metal a flat blank having a body and projecting finger portions, then rolling said blank to form a tubular coiletwith spaced ed es from end to end, then providing one en of the colletwith'threads and compressing a portion of said colletto form tapered, resilient, gripping fingers 25. The method of making a feed collet which consists in'stamping from sheet metal a flat blank comprising a body portion and a gripping portion, then rolling said blank into tubular coiled spring form with spaced edges from end to end, one of said edges having at the body portion thereof a project-ion, and said body having a shoulder therein, then providing the body end with threads and compressing the gripping portion to form tapered resilient fingers.

26. The method of making a feed collet which consists in stamping from sheet metal a relatively flat blank havln a body portion and a gripping portion, an a projection at one side of the body portion, then coilin said blank into tubular form with space edges from end to end thereof, providing the body portion with threads and compressing the gripping portion to form a plurality of tapered, resilient, gripping fingers, and providing said gripping fingers with gripping surfaces conforming to the shape of the stock to be fed.

Signed at Cleveland, Ohio, this 16th day of January, 1922.

OSCAR A. SMITH. 

